ok i've noticed something odd with my c6 tranny. if i have the gear selector in 1st gear it stays in first gear and works perfectly. if i put it in 2nd gear it starts off in second gear and stays in second. if i put it in Drive it starts in second gear until i give it a little extra throttle when it downshifts into first. how do i fix this?

 

You might need to adjust the linkage to the tranny. When placed in 2nd, the trans will always be in 2nd. When placed in 1st, it will always be in 1st. When placed in drive, it should take off in 1st and shift to 2nd and then 3rd. I'm sure you knew this, but it sounds like the linkage could be off a little. Try moving the shifter up towards nuetral just a tab bit and see if it takes off in 1st. Flooring it will pull on the kickdown cable and make it go to the lowest gear possible depending on how fast you're going.

 

i thought that if you had it in second gear it would start in first then go up to second, but no higher.

 

As did I...both of my family's automatics do that. Granted, they're both GMs as well...so that could definetly be the difference.

 

my mom's 2001 explorer works the way i described. first gear starts in first and stays in first. second gear starts in first and shifts to second, third gear starts in first shifts to second then third. so do i understand this correctly. on my C6 tranny, if i selecg second gear it is SUPPOSED to start in second gear and stay in second gear? why would you want to start in second gear?

 

my mom's 2001 explorer works the way i described. first gear starts in first and stays in first. second gear starts in first and shifts to second, third gear starts in first shifts to second then third. so do i understand this correctly. on my C6 tranny, if i selecg second gear it is SUPPOSED to start in second gear and stay in second gear? why would you want to start in second gear?

 

Ford and Honda are the only two manufacturers that I've ever noticed that do this in terms of putting it in 2nd. It's a great idea to be honest. Say you're on an icy road. Put it in 2nd to get the RPM's up a little without getting as much wheelspin, if any at all. All Ford automatics and any Honda I've ever been in has done this.

 

oh cool, kinda like the "snow" or "winter" buttons on isuzus and lexus.

 

I know the C6, C4, E4OD, AOD, 4R70W, AODE, 4R100, A4LD, and 5R110's all do this. I don't know what your Mom's Explorer has, but I'm willing to bet it either has the A4LD (or whatever the newest version is) or the 4R70W.

 

As for the starting in second in Drive, check your vacuum modulator. I had this problem on a new modulator for the C6 I built for my 78. If it's out of adjustment it will want to start in second if there's enough vacuum. Turning the screw in raises the shift points slightly. If you pull the line off the modulator you'll see the adjustment screw. If that doesn't help you may need a new modulator.

 

where would this modulator be located?

 

It should be at the back end of the oil pan, near the tail of the tranny, on the right (passenger) side, just above the pan gasket, and pointed toward the back of the car. You'll find a vacuum line attached to it.

If the modulator itself is bad, you'd probably notice the tranny fluid level dropping on a regular basis, depending on how it's driven. Lots of high-speed highway miles, lotsa tranny fluid disappearing. Buzzin around town, a little less fluid consumption. Sometimes, if there is enough fluid going through, it'll leave a little grey ash from the detergents in the fluid at the tail pipe. Pull the vacuum line up in the engine compartment, and check it for oily residue. That's a sure indication you're pulling tranny fluid up there.

One thing of note here, though, is check very closely before you disturb it. It's possible that it's been replaced before (I've put two on my '86 T-Bird with a C6). If someone else has replaced it, sometimes, the pin to the pitot valve in the valve body will get dropped. When this happens, that's exactly the behavior you'll get with the shifting. I didn't notice the pin on mine until I cleaned out the bucket I used to catch the fluid when I was changing it. Don't get on it too hard, or you're gonna slip the bands on 2nd. C6's make some pretty weird noises when this happens.

You can replace it without draining the tranny, but gotta be fast, and expect to wear some of the fluid. Make sure you have the new valve in one hand while you're pulling the old one out with the other. If you can get a replacement pin to put in the new valve, even better. Otherwise, you gotta pull and re-insert the valve 3 times to retreive the pin from the old valve, and get it installed with the new valve. Another option will be to get you a nice rubber plug to cram in the hole while you retreive the pin from the old valve. That way, it's open twice, and you only get two oil baths. Get the new valve in (WITH THE PIN) and top her off with fluid, and voila, it should shift normally again. If not, it's probably time to take a good look at the tranny.

If you put the tranny in 2nd, it should start in 1st, and shift to 2nd, no doubt about it. I had the C6 in a '76 Mercury Monarch, and in my '86 T-Bird. Good tranny, very tough tranny.

 

Moved to appropriate forum per our "Read First!" annoucement at the top of the 87-96 forum.

 

ok so which is it? when i put the gear selector in 2nd gear which gear should the truck take of in from a stand still?

 

When you put the selector into 2nd gear, it will take off from a stand still in 2nd, and will stay in 2nd no matter what.

From a dead stop, put it into 2nd and stand on the throttle. Do the same thing with the selector in 1st. You will definately tell the difference.